Ok, so the experiment worked... I did get flamed, although amicably, by Gordon Watts (see here) for having written that the D0 interaction region of the Tevatron tunnel is "uninstrumented"... Quite the opposite, as the picture on the left shows.
The D0 detector was the second one to fit in the Tevatron tunnel. At first there was CDF only, which started data taking in 1987 (wow, 18 years ago! and some of its components are still producing good data now!). While CDF was built with the primary goal of discovering the top quark (which we did in 1995), D0 was foremost designed to provide as good a measurement as possible for the mass of the W boson, through a very precise determination of the energy of the decaying electron and neutrino.
Due to the fact that CDF had no competitors for a while, I have the feeling that our collaboration has developed some sort of snobistic attitude toward the particle physics community. Let me explain.
When you do particle physics, you want to publish your results quickly, to further the understanding of fundamental interactions and provide food for thought for theoreticians worldwide. You want it quick because it would be a crime to withhold information, and because you are competing against other experiments who can publish before you, and later get more money than you from the funding agencies.
The latter of these reasons did not hold for CDF in the early days, and we developed a very baroque mechanism to ensure that our results were triple-checked, as-good-as-possible, unquestionable. We designed pre-blessing of results at physics meetings, after which the last physicist in our 500+ collaboration might question them, ask for more checks, require changes. Only after these are fulfilled, one can go for the blessing of a physics results. But, after a result is blessed, the publication process begins. A godparent committee is formed, which will look at your analysis with a magnifying lens, and ask you for endless verifications that usually last more than 6 months. When you are past that, you produce a paper draft, and the whole collaboration can read it, send you their objections (sometimes futile, sometimes inflamatory). You have to answer them all with a polite smile. Then you can produce a second draft, that - godparent committee willing - can be sent for further scrutiny to the collaboration, and again receive a s***load of comments, corrections, etcetera. Only then you do a paper seminar to the collaboration (last chance for the distracted ones to have a shot at you), and the paper is sent to either of a couple of scientific magazines that are renowned for their pickiness (the magazines will have of course their own review process, will assign referees, and the process of review continues...)
CDF still pays for the slowness of this mechanism. It does not matter to some of my peer, who think that the most important thing is to be absolutely sure that the results are perfect. I disagree. I think it is more important to spend our time doing research than to pick on the weak sides of our fellow's research. If one paper in a hundred presents a wrong result (wrong here meaning that a systematic uncertainty was underestimated, or that a slightly incorrect claim is made, or the like) so what ? Other experiments will measure the same quantity, and will prove you wrong in the long run. But withholding results for a year to the outside world (which in the end means 5000 physicists - the readers of those scientific papers - as opposed to the 500 that sign it) is not a smart thing to do.
Going back to D0: it did much more than measuring the W mass - and indeed better than us albeit only slightly - during Run I (1992-96). Their detector did not have a magnetic field then, which severely limited their reach in important fields such as B physics (they have one now) since charged track did not get a measurement of their momentum, not being bent in the transverse plane. But they co-discovered the top quark, and now, in Run II, they are even more serious competitors to CDF. Good luck, fellows!
T. CONGRATULATIONS on finally receiving some outcomes that you wanted with this experiment. I know you have been really looking forward to this. It's like people say in life, when you stop looking for things, that is when they reveal themself to you. It was good to see you so happy about this event. I am happy for you and proud. Talk to you soon. Love, G
Posted by: Gina LePar | January 16, 2005 at 07:54 AM